This invention relates to a method and apparatus for fault reporting and more specifically to arbitrating the reporting of a circuit board address when a fault occurs on the circuit board.
As is well known, it is desirable to provide apparatus that automatically reports the address of a faulty circuit board to a control processor. Upon receiving such a report, the control processor can log the address into its own internal memory, and then change the operational configuration so that the system continues to operate with the faulty circuit board off line.
One prior art approach for providing the address of a faulty board to a control processor is by the control processor polling each of the circuit boards individually. Typically, each circuit board is polled over a dedicated select line interconnecting each circuit board to the control processor. Thus, if there were ten circuit boards, ten select lines would be required. The circuit boards are also coupled to the control processor with a common data bus. When the circuit board detects a fault and when the faulty board is polled, the address of the faulty board is fed to the control processor over the common data bus.
This method of address reporting has the drawback of requiring that a separate select line be coupled to each of the circuit board via a back plane. Additional select lines increase back plane complexity. Added complexity may increase the system cost and decrease the system reliability.